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Arouse the DAMPFHAMMER!
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The intake should be at 26° and the exhaust at 25°.
I appreciate your answer and specification of the valve relief angles.

Was the block or cylinder head decked?
If decked means milled, yes it was:



Was P-to-V checked with a torqued head gasket (a new one vs. an old one)?
Torqued to spec with an old head gasket.

I assume it was checked with rings installed on the piston?
Yes Sir.

Regarding cutting the pockets on the piston, there is room on that particular piston to safely cut the pockets deeper. For the intake you can go 0.8mm and exhaust up to 2.11mm deeper.
I appreciate your tolerated measures to that :up:

Markus
 

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Marko, these guys are not far from Cologne...just for your information:

BAR-TEK® Motorsport GmbH
Geschaftsführer: Bartek Bartoszewicz
Im Rauschen Auel 3
51491 Overath-Brombach
email: info(at)bar-tek.de
www.bar-tek-tuning.de

Markus

I have been on that site, but they do not list any products for Honda engines. Hence I stated to look elsewhere writing to shops having the pistons listed I wanted. They all eventually came back telling me they cannot get them anymore as they are discontinued. :-(

I have already purchased the supertech pistons with a suitable chamber volume, but they need some fettling. The outer walls of the valve pockets are too narrow. They might melt and casue the piston crown to break.
I need to shave these walls down a tad. :-(
 

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If decked means milled, yes it was:



Torqued to spec with an old head gasket.


Markus
So these are two variables that could cause the difference in angles. Slight variations into how the block was milled could contribute to it being off, as well as using an old head gasket that has lost it's intended crush. We always recommend using the head gasket that you plan on running to check p-to-v to ensure an accurate reading.

Not saying definitively that these were the causes, but could these two variables combine to produce an angle that appears to be off 2°? Absolutely. Like I mentioned though, there is enough room there to cut the pockets deeper should you need to do so.
 

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That brings up another question i have.

In the past i have taken a dremel to the sharp valve reliefs to just round them off. There has also been some discussion about 'clearancing pockets' of the valve reliefs.

Is doing this via dremel safe? do I need a more precise tool or should I only trust a machine shop? I had no issues in the past but would like to understand how much modification is too much to do at home.
 

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Premium Member
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That brings up another question i have.

In the past i have taken a dremel to the sharp valve reliefs to just round them off. There has also been some discussion about 'clearancing pockets' of the valve reliefs.

Is doing this via dremel safe? do I need a more precise tool or should I only trust a machine shop? I had no issues in the past but would like to understand how much modification is too much to do at home.
The best way to knock any sharp edges off is with a buffing wheel on a grinder, but some sort of similar attachment on a Dremel would work fine.

As far as cutting valve pockets go, the first thing to keep in mind is whether or not you can do it safely to begin with. A lot of it depends on the application and the forging used, but certain pistons don't have enough meat in that area to safely cut any more material without compromising the integrity of the part, so be sure to check that first. As far as how to cut it, the best way is to put it in a mill and use a cutter, but I realize not everyone has a mill at home or even has that option. Using other cutters shouldn't be much of an issue other than the loss in accuracy as a function of using a hand tool, as long as you make sure that the cut is cleaned up, you don't want any sharp edges or rough areas left over for hot spots to start. Best case scenario is to definitely take it to a machine shop though, it's not worth it to save a little bit of money to have an issue and cost you dearly.
 

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Arouse the DAMPFHAMMER!
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As far as cutting valve pockets go, the first thing to keep in mind is whether or not you can do it safely to begin with...it's not worth it to save a little bit of money to have an issue and cost you dearly.
Thanks, I only thought about a mill machine as 0.8 mm isn't much for some pieces of tools :D. Of course every edge would get a phase (smoothing) to prevent local hot spots and of course specifications for radial valve clearance will be adhered to.

I appreciate your time and answers here :up:

Markus
 
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